I will conduct research on the structure and expression of genetic markers at chromosomes 11, p15, especially the Ha-ras-1 proto-oncogene, in acute myeloid leukemia (AML) with abnormalities of chromosome 11 at P15 region. The 11 P15 abnormality is the second most common chromosomal change found in Thai AML patients and its occurrence is related to short survival of the patients. It is interesting to substantiate that the Ha- ras-1 proto-oncogene as well as other genes normally localize on chromosome 11 P15 (such as insulin-like growth factor II gene (IGF II) and Beckwith-Weideman Syndrome related gene (BWS)) change their structure and/or are activated in AML patients with abnormalities of chromosome at this region. To meet the goal, various procedures will be used such as in situ hybridization of metaphase chromosome. DNA analysis by Southern blotting, gene expression analysis by Northern blotting, etc.